I don't know what you told that technician, but try this. Download some of your pictures and videos to your computer. If the downloaded pictures look fine on your computer, then the technician was right, and it's probably just a loose LCD ribbon cable connection.
BUT if the downloaded pictures also look blurry with stripes, then it's probably a faulty CCD imager. If so, Canon should fix this for you for free, including free shipping both ways. This is regardless of your camera's warranty status. BUT MAKE SURE you tell the technician this time that it is showing up on your DOWNLOADED pictures. I recommend trying again, and hope for a more knowledgeable tech on the line this time. Please check the following two links for more info:
Applicable cameras include:
A40, A60, A70, A75, A80, A85, A95, A300, A310, S1 IS, S60, S200, S230, S330, S400, S410, S500, SD100, SD110, IXUS V2/300/400/430/500, IXY Digital 200a/300a/400/450/500